i created a blank app bar in an activity, inserted a text and everything was working fine, i modified the code a little and now the application name shown in the app bar, how to remove it and where did it come from? here is the design and the output
and here the code
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:theme="?attr/actionBarTheme"
android:minHeight="?attr/actionBarSize"
android:id="@+id/toolbar"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
/>